The Department of Defense now has about 27,000 vehicles in Iraq—and every one of them gets lousy gas mileage. To power that fleet the Defense Logistics Agency must move huge quantities of fuel into the country in truck convoys from Kuwait, Turkey, and Jordan. All that fuel gives American soldiers a tremendous battlefield advantage (in communications, mobility, and firepower, among other things). But overseeing and carrying out this process requires the work of some 20,000 American soldiers and private contractors. Every day some 2,000 trucks leave Kuwait alone for various locales in Iraq.
In addition to the challenges posed by the volume of fuel needed, the Army's logisticians must deal with the sheer variety of fuels. Although the Pentagon has tried to reduce the number of fuels it consumes, and now relies primarily on a jet-fuel-like substance called JP-8, the Defense Energy Support Center is currently supplying fourteen kinds of fuel to U.S. troops in Iraq.
In short, the American GI is the most energy-consuming soldier ever seen on the field of war. For computers and GPS units, Humvees and helicopters, the modern soldier is in constant need of energy: battery power, electric power, and petroleum. The U.S. military now uses about 1.7 million gallons of fuel a day in Iraq. Some of that fuel goes to naval vessels and aircraft, but even factoring out JP-5 fuel (which is what the Navy primarily uses), each of the 150,000 soldiers on the ground consumes roughly nine gallons of fuel a day. And that figure has been rising.
Some of the rise in consumption is due to the insurgents' use of improvised explosive devices, which account for about 30 percent of all American combat deaths since the occupation began. As John Pike, the executive director of GlobalSecurity.org, told me, "This is a war of convoy ambushes and car bombs. There is no front line." Perhaps hundreds of American vehicles have been destroyed by IEDs (the exact number is classified), and hundreds of soldiers—many of them guarding convoys—have been killed or injured by them. (And more than sixty-five private contractors are known to have been killed by convoy attacks or IEDs since July of 2003.) Cheap, easy to use, and highly effective, IEDs have forced the Americans to add armor to their fleet of Humvees in Iraq. A fully armored Humvee weighs more than five tons—and requires a larger engine and heavier suspension than the non-armored model. The Army also recently allocated more than $500 million to add armor to its utility trucks.
The added armor will help protect U.S. soldiers from IEDs and snipers—but it also means higher fuel consumption for their vehicles. Which means, in turn, that more tanker trucks will have to be driven into Iraq—and those trucks will provide more targets for the insurgents, who have become skilled at attacking them. It's difficult to guard them all. When insurgents see that American patrols are increasing in one region, they can quickly and easily shift their attacks—on fueling stations, pipelines, truck convoys, refineries—to another region.
It's a vicious cycle: attacks on convoys produce a need for more armor, which produces a need for more fuel, which produces larger convoys, which produce more targets for attack. Over the past six months the Army and the Air Force have had to specially train more than 1,000 additional soldiers to perform convoy security. One tank commander, who returned from Iraq last spring, told me that he had been so concerned about his supply lines that he had stationed sentries at one-mile intervals along the highway in his sector.